The National Weather Service has issued a Red Flag Warning – for a high risk of wildfire – until 6 p.m. Tuesday for the mountains of Los Angeles and Ventura counties.

The NWS said gusty northeast winds, low humidity and dry vegetation raises the risk of wildfire in the Santa Clarita Valley, the Angeles National Forest, the Los Padres National Forest and the San Gabriel and Santa Monica mountains.

Forecasters said gusty Santa Ana winds will be strongest in mountain passes and canyons of the Los Angeles and Ventura counties, with gusts between 30 and 40 mph common. Wind gusts are expected to be between 25 and 35 mph through early Tuesday afternoon in the valleys.

The NWS forecasts warmer weather for much of Southern California, with highs in the 70s and 80s, including 84 degrees in downtown Los Angeles.